SEAL-O-RING 0951600 - Caterpillar

Probable Causes
Intermittent diagnostic codes
Check engine lamp
Warning lamp
Cruise control set/resume switch
Short in vehicle harness
Service engine soon lamp (GM)Recommended Actions
Note: GM vehicles refer to the Check Engine Lamp as the Service Engine Soon Lamp.Perform the following diagnostic procedures in order:Intermittent Diagnostic Codes
Use Caterpillar Electronic Technician (ET) to check for any diagnostic codes that may be logged or active. Check for any intermittent diagnostic codes.Check Engine Lamp
In order to check the check engine lamp, place the ignition key switch in the ON position while the engine is off. The check engine lamp should turn on. Then, the check engine lamp should turn off. The check engine lamp will flash if there is an active diagnostic code.
Place the ignition key switch in the OFF position.
If the check engine lamp did not operate correctly remove the terminal for the check engine lamp (terminal 28) from the 70-pin connector at the Engine Control Module (ECM).
Connect the check engine lamp (terminal 28) to the ground stud. Place the ignition key switch in the ON position.
Observe the check engine lamp. If the check engine lamp comes on there may be a problem with the circuit. Place the ignition key switch in the OFF position. Check the power connection and the ground connection of the ECM. Refer to Troubleshooting, "Check Engine Lamp Circuit - Test" for additional information.If the lamp does not come on there may be a problem with the lamp. Place the ignition key switch in the OFF position. Check the lamp in order to ensure that the lamp is not burned out. Also, check the wiring in order to ensure that there is not an open circuit or a short circuit.Warning Lamp
In order to check the warning lamp, start the engine. The warning lamp should come on for at least two seconds. Then, the warning lamp should turn off. The warning lamp will remain on or flash if there is a problem with the engine.
Place the ignition key switch in the OFF position. The engine should be off.
If the warning lamp did not operate correctly remove the terminal for the warning lamp (terminal 29) from the 70-pin connector at the ECM.
Connect the warning lamp (terminal 29) to the ground stud. Place the ignition key switch in the ON position.
Observe the warning lamp. If the warning lamp comes on there may be a problem with the circuit. Place the ignition key switch in the OFF position. Check the power connection and the ground connection of the ECM. Refer to Troubleshooting, "Warning Lamp Circuit - Test" for additional information.If the lamp does not come on there may be a problem with the lamp. Place the ignition key switch in the OFF position. Check the lamp in order to ensure that the lamp is not burned out. Also, check the wiring in order to ensure that there is not an open circuit.Cruise Control Set/Resume Switch
Connect Cat ET to the cab data link connector. Place the ignition key switch in the ON position. Observe the status screen for